1. Field of the Invention
The present invention relates to a recording medium having a recording surface to record information thereon and having a position recognition structure for recognizing a position on the recording surface, a position recognition apparatus for recognizing the position on the recording surface, and a position recognition method.
2. Description of the Related Art
As large-capacity recording media used for various apparatuses, such as a computer, a player and a recorder for music and video or the like, and a car navigation apparatus, there are a compact disc, a DVD, a hard disc and the like. With respect to any one of the recording media, it is possible to record a huge amount of information onto a recording surface formed on the disc at high density.
In such large-capacity recording media, it is required to accurately recognize a recording position of the information on the recording surface. It is also required to set a rule about the recording position and arrangement of the information, and it is required to record and read the information highly accurately according to the rule.
In response to the requirement, for example, in a currently used DVD-RAM, a land-groove method is adopted as its recording method. Namely, on the recording surface, grooves are formed in the circumferential direction. The information is recorded onto the grooves and onto the lands (i.e. a place between the grooves). By this, the information is defined by the grooves, and arranged and recorded in the circumferential direction of the disc. The lines of the information arranged in the circumferential direction of the disc in this manner correspond to tracks. Moreover, each track is divided at predetermined intervals in the circumferential direction of the disc. The divisional small areas correspond to sectors. In each of the sectors, address pits having a bumpy shape are formed. Moreover, a wobble having a predetermined cycle is formed on the groove, which is formed on the recording surface, and on the basis of the cycle of the wobble, it is possible to estimate a position of the address pit.
In the DVD-RAM having the recording method as described above, it is possible to accurately recognize the record position of the information, and it is possible to record and read the information highly accurately. This is because the groove formed on the recording surface is an absolute (or immovable) standard for the position recognition.